Device for pressing out a fluid from a material in pieces



April 12, 1955 B. M. MILLGARD DEVICE FOR PRESSING OUT A FLUID FROM AMATERIAL IN PIECES Filed May 51 1951 United States Patent DEVICE FGRPRESSING OUT A FLUID FROM A MATERIAL IN PIECES Bror Manne Millgard,Ljusne, Sweden Application May 31, 1951, Serial No. 229,115

1 Claim. (Cl. 100-95) irrespective of whether amount of material presentis less than the maximum capacity of the pressing device.

Another object of the invention is to construct a device capable ofpressing the material for whatever length of time may be necessary forthe complete outflow of the water, pressed out.

Another object of the invention is the provision of a device, whichpermits a sutficiently high pressing force without any possibility forthe material to be jammed in the device causing a break down or damageof the machine.

A device according to the invention is provided with a primary and asecondary reciprocating press member registering with each other, saidpress members being forced one against the other with the same orsubstantialy the same pressure.

The invention is characterized by the fact, that when the pressureacting on said secondary press member has reached a predetermined value,said pressure is maintained substantially constant so that a furtherincrease of the pressure acting on the primary press member, displacessaid primary press member together with the pressed material and thesecondary press member thereby during maintenance of the press intensitydisplacing said material in the moving direction of said primary memberto a position for removing of a greater or lesser quantity of thepressed material.

One embodiment of the invention is schematically shown in theaccompanying drawing, partially in section.

The embodiment shown in the drawing is assumed to be connected to ahydraulic pressure system. To the opposite ends of a hydraulic cylinder1 with a piston 2, conduits 3, 4 are leading from a slide valve 5. Thisslide valve controls the communication between said conduits 3, 4 and afeed line 6 for pressure medium on one hand and two outlets 7 and 8 onthe other hand.

The piston 2 is fixed to a tubular piston rod 9, the

outer end of which is shaped like a press head 10, forming the primarypress member, said piston 2 being slidable in a press chamber comprisingtwo sections 11a, 11b. Section 1111 is situated nearest the cylinder 1and has a filler opening 12 for the material to be pressed. The othersection 11b of the pressing chamber has a cylinder shape so that thepress-head of the tubular piston-rod 9 fits therein as a piston. Boththe circumference wall of the section 11b and the end wall of thepress-head 10 are perforated, said tubular rod having in its inner end adrainage opening 13 for the water. The outer end of the cylinder 11b iscovered by a movable counterpress plate 14, said plate also beingperforated at 14'. The counterpress plate 14 forming the secondarypressmember is the outer end wall of a hollow piston rod 7 15 for apiston 16 in a hydraulic cylinder 17. For draining the liquid enteredinto the hollow piston rod 15 an aperture 15' is provided in itscircumferential wall at the lowermost point thereof near the end wall14. Opposite ends of the cylinder 17 are connected to conduits 18, 19connected to a slide valve 20 through conduits 22, 21 and 24,respectively. The conduit 19 permanently communicates with the conduit 4via a conduit 23. The housing of the valve 20 communicates with theconduit 3 through a conduit 25, said conduit 25 in turn being leadingvia a ice conduit 26 to the upper end of said valve housing. Against thelower end of the valve 20 abuts a compression spring 27.

A knife 28 is mounted for transverse reciprocation at 32, 33 leading toopposite ends of the cylinder 30, an

inlet 34 for the pressure medium and two discharge conduits 35, 36. Thevalves 5 and 31 are operated by solenoids 37 and 38 respectively, andthe valve 20 is operated in one direc' tion by the hydraulicpressurefrom the conduit 26 and; in the other direction by the spring 27.

The solenoid 37 is controlled by a timing relay 39, said relay 39 beingcoupled in a circuit 40 between the solenoid 37 and a contact member 41,said contact mam"- ber being arranged in the path of warm 42 attached tothe tube 9. The circuit of the solenoid 37 comprises a conductor 43 to acontact member 44 arranged in the path of an arm 45 attached to theknife 28. The circuit of the solenoid 38 comprises a conductor 46 to acontact member 47, adapted to be operated by the arm 42 and also aconductor 48 to a contact member 49 arranged in the path of the arm 45.In the following the operation of the valves will be more clearlydescribed in combination with the descrip tion of the manner of workingof the machine. In the drawing the machine is shown in a position atwhich the piston 2 is moved to its right end position.

Consequently, the tubular piston rod 9 and the press-head 10 are movedto their end-positions. The counterpress plate 14, which is normallypressed against the mouth of the cylinder 11b of the press chamberismoved a small distance away from the mouth of the cylinder by thematerial 50, which has been packed in said cylinder 11b as described inthe following.

At the beginning of the pressing operation the piston 2 was situated inits left end position in the cylinder 1 and the press head 10 of thepiston rod 9 had reached the left end wall of the filler opening 12.Thereafter, the valve 5 takes the position shown in the drawing, therebysupplying pressure medium to the left end of the cylinder 1 comprisingthe piston 2 via the pipe 3. The valve 20 also takes its shown positionso that the pressure medium from the pipe 3 is supplied to the right endof the piston 16. At the first pressing step the counterpress plate 14is pressed by the same force as the press head 10 against the materialpacked in the cylinder 11b. In order to permit the packed material to beforced forward through the cylinder 11b the pressure in the counterpresscylinder 17 must be prevented from exceeding a certain limit ofpressure, said limitation being afforded by the valve 20. This valve isactuated in one direction by the pressure in the conduit system 3, 25,26 and in the other direction by the spring 27, said spring beingdimensioned to be compressed when the pressure on the upper end of thevalve has reached a certain value. Then the valve 20 is forced downwardwhereby it closes the supply of pressure medium from the pipe 25 to theright end of the counterpress cylinder 17. At the same time acommunication is attained from the conduit 18 via the conduits 22, 24with the conduit 23, said conduit 23 being in communication with theoutlet 8 in the position shown in the drawing. At this time, both sidesof the piston 16 are in communication with said outlet 8. When thepressure in the press cylinder 1 increases above the pressure in thecylinder 17 limited by the spring 27, the press head 10 will displacethe packed material 50 in the cylinder 11b, thereby moving theconnterpress piate 14 to the right, causing a portion of the material tobe fed out of the cylinder 11b, as is shown at 51.

When the press head 10 has reached its outer end position (to the rightin the drawing) the arm 42 attached to the piston-rod 9 operates thecontact member 41, said member energizing the timing relay 39.

This relay 39 is adjustable in order to permit the press head 10 toexert a force on the material during a neces- Patented Apr. 12, 1955sary period. When this period is finished, the timing relay energizesthe solenoid 37, said solenoid operating the valve 5, so that thepressure in the cylinders 1 and 17 is reversed, whereby the pistons 2and 16, respectively, are moved back to their initial. positions.When-the piston 2 has reached its left end position, the arm 42 operatesthe contact 47, said contact thereby energizing the solenoid 38. Saidsolenoid-operates the valve 31 causing the piston 29 tomove the knife 28downwards in order to cut off the portion 51 of the material intheformof a briquette to be removed. When the knife has reached its lowerend position, the arm 45 operates the contact 49 in order to disconnectthe solenoid 28 and, consequently, the valve 31 is operated. and theknife is moved back to its initial position. In this position the arm 45operates the contact 44, which disconnects the solenoid 37, therebycausing thecounterpress piston 16 to move forward for pressing thematerial, which in the meantime has been supplied through the feedopening 12.

, During the pressing of this material the water is pressed out anddrains off through the openings in the cylinder 11b, the press head 10and the counterpress plate 14. Owing to the drainage of water in alldirections the pressing device according to my invention secures a gooddrying effect. The drying effect is improved by the fact that thematerial to be severed at the end of the pressing operation is entirelyfed out of the cylinder 11b. The period necessary for drainage of thewater is easily regulated by the'timing relay 39. The cylindricalsection 11b of the press chamber can be made so long that the sameamount of material can be subjected to several repeated pressingoperations before the final feeding out. The mouth of the press chambercan be formed for the purpose of the best drainage effect. As the presshead does not move throughout the whole length of the press chambertheouterend portion of the cylinder 11b can be provided with adecreasing or increasing area towards the mouth or it can be entirelycylindrical, depending on the properties of the material to be pressed.This may not be permitted in presses, by which the press member is movedthroughout the entire length of the press chamber.

.The press head 10 should be constructed in such a w-ay'as to secure auniform distribution of the material throughout the whole cross sectionof the cylinder 11b. Especially with a horizontal arrangement of thepressing device the material will collect at the bottom of the presschamber, if at each piston stroke the material does not fill up thepressing chamber completely. At incomplete filling up of the presschamber the material to be pressed must be given an upwards directedmovement, said movement being obtained by use of an oblique or a concavepressing surface, as shown in the drawing. For the purpose of cuttingoif the portion of the material extending above the path of the pistonrod 9 in the filler opening the press head is provided with an annularknife 52 cooperating with a ring 53 of similar material. At the outerend of the press chamber the knife 28 is arranged to slide against aring 54 of knife steel, fixed at the mouth of said end.

I claim:

A device for pressing out a fluid from a material in pieces, comprisinga perforated press chamber for receiving said material, said chamberhaving an open end surrounded by an annular end surface forming anoutlet for the material pressed, there being an opening spaced in saidchamber from said open end for introducing the material to be pressed,aprimary press member within said chamber for acting on the material inthe direction towards the open end of the chamber, a secondary pressmember having a perforated flat end surface greater in periphery thanthe periphery of said outlet'and provided outside said chamber oppositeto and facing the open end thereof and adapted to bear against theannular end surface surrounding said open end, means for reciprocatingsaid primary press member, and means for yieldingly holding saidsecondary press member against said annular end surface by a restrictedforce lower than the maximum force that can be exerted by said primarypress member, a knife adapted to reciprocate transversally close to theopen end of the press chamber for cutting the material fed out inslices, means for reciprocating said knife, and means for controllingthe movement of said knife in response to the movement of the primarypress member.

References Cited in thefile of this patent UNITED STATES PATENTS FranceDec. 15,1934

